ppt on manufactured sand

PPT on Manufactured Sand: An Overview

This presentation provides a comprehensive analysis of Manufactured Sand (M-Sand), a crucial alternative to natural river sand in the construction industry. It will define M-Sand, detail its production process, and objectively compare its properties with natural sand. The core advantages and challenges of adoption will be discussed, supported by real-world case studies. Furthermore, the presentation will explore quality control parameters, market trends, and practical FAQs to offer a holistic understanding of its role in sustainable construction.

1. Introduction to Manufactured Sand
Manufactured Sand is fine aggregate produced by crushing hard granite or basalt rocks through a three-stage crushing and screening process. The resulting particles are cubically shaped, graded, and washed to remove excess fines. With the depletion of natural river sand and environmental restrictions on its mining, M-Sand has emerged as a technically sound and environmentally responsible substitute, particularly for concrete and plastering work.

2. Production Process & Key Characteristics
The typical production involves:

• Primary Crushing: Jaw crusher breaks down large rocks.
• Secondary & Tertiary Crushing: Cone crushers or Vertical Shaft Impactors (VSI) crush material further. VSI is preferred for achieving the desired cubical shape.
• Screening: Particles are screened to separate correct sizes.
• Washing: Optional step to remove micro-fines (below 150 microns) if required for specific applications.

Key characteristics of quality M-Sand include angular particle shape (enhancing interlocking), consistent gradation, and minimal organic or clay impurities.

3. M-Sand vs. Natural River Sand: A Comparative Analysis

Parameter	Manufactured Sand (M-Sand)	Natural River Sand
Source	Crushed hard rock (Granite/Basalt)	River beds & banks
Particle Shape	Angular & Cubical	Rounded & Smooth
Gradation	Controlled & consistent	Variable, depends on source
Fines Content	Can be controlled during washing	Often contains silt & clay
Moisture Content	Low & controllable	High & variable
Concrete Workability	May require slight adjustment in mix design due to angularity	Generally good due to smoothness
Strength	Higher compressive strength due to better interlocking	Slightly lower comparative strength
Environmental Impact	Sustainable; reduces riverbed degradation	Unsustainable mining causes ecological damage

4. Advantages & Challenges

• Advantages:
  • Sustainable: Conserves river ecosystems.
  • Consistent Quality: Uniform gradation leads to predictable concrete performance.
  • Availability: Reliable supply independent of seasonal bans.
  • Enhanced Strength: Angular particles improve mechanical properties of concrete.
• Challenges:
  • Initial Perception: Resistance from traditional builders.
  • Micro-fines: If not controlled, can increase water demand in concrete.
  • Plant Setup Cost: Requires significant capital investment.
  • Mix Design Adjustment: Engineers/contractors need training for optimal use.

5. Real-World Case Study: Adoption in Major Infrastructure
A prominent example is the use of M-Sand in the construction of the Chennai Metro Rail Project (Phase I) in India. Facing acute shortages and regulatory restrictions on river sand sourcing, project authorities mandated the use of high-quality manufactured sand for structural concrete.

• Solution Implemented: Sourced M-Sand from approved quarries using VSI crushers with integrated air classification systems to control fines content below 12%.
• Process Adjustment: Concrete mix designs were rigorously lab-tested and optimized with appropriate water-reducing admixtures to counterbalance the angular shape of M-Sand and achieve required workability for complex reinforced sections.
• Outcome: The project successfully utilized over 2 million cubic meters of concrete made with M-Sand. It demonstrated comparable 28-day compressive strength and durability metrics while ensuring an uninterrupted supply chain, contributing significantly to timely project completion.

This case validated M-Sand's technical feasibility for large-scale, high-specification infrastructure.

6. Quality Control Parameters
Critical tests for M-Sand include:

• Particle Size Distribution (Gradation): Must conform to IS 383 or ASTM C33 zones.
• Fineness Modulus: An indicator of coarseness/fineness.
• Silt & Clay Content (≤ 3% as per IS codes).
• Shape Test (Flakiness & Elongation Index): Ensures cubical particles.
• Strength Tests (Concrete Cube Test): Ultimate performance validation.

7. Frequently Asked Questions (FAQ)

1. Does using M-Sand make concrete weaker?
   No. When used correctly with adjusted mix designs, concrete with M-sand often exhibits higher compressive and flexural strength due to better mechanical interlocking of angular particles.

2. Can M-Sand be used for plastering?
   Yes, specifically graded plastering sand is produced by removing excess fines (<150 microns). This prevents issues like cracking or poor finish associated with unwashed crusher dust.

3. Is M-Sand more expensive than river sand?
   Initially, it can be comparable or slightly higher depending on location and transport logistics. However, considering consistent quality reduced wastage reliable supply without price volatility long-term cost benefits often favor m-sandin large projects

4 What is the main environmental benefit?
The primary benefit is halting destructive riverbed mining which causes erosion loss biodiversity groundwater depletion damage bridges

5 How do you handle high fines content in m-sand
High fines can managed through washing process at plant site adjusting water cement ratio using chemical admixtures like superplasticizers maintain workability without compromising strength